Manufacturing method of white polyester reflective film, reflective film thereby, and reflective sheet using the same

The present invention provides a manufacturing method for a white polyester reflective film comprising: a first step of manufacturing an undrawn sheet by molding a raw composition which contains uncommercialized hollow particles and white inorganic particles in polyester resins and polyester resins respectively through an extruder; a second step of cooling the molded undrawn sheet; a third step of manufacturing a uniaxially drawn film by uniaxially drawing the cooled undrawn sheet; a fourth step of manufacturing a biaxially drawn film by biaxially drawing the uniaxially drawn film; and a fifth step of heat-treating the biaxially drawn film. The manufacturing method for the present invention is able to minimize breaking frequency in a biaxially drawing process by controlling the number and size of the hollow particles. A reflective film manufactured thereby improves optical properties by doubly giving photorefraction to the pores of the inner space of the hollow particles except for pores produced by making uncommercialized hollow particles as nucleuses in the polyester resins of the raw composition.